A. Present simple or present progressive? 1. - Where Mr Ross (live)? - I (not know). 1 (think) he (live) in the next street. 2. - John (smoke)? - He used to. But now he never (touch) a cigarette. He gradually (become) quite fit. 3. Ice (melt) in a warm climate. 4. I usually (not eat) sweet things. But today it's Tom's birthday, so I (eat) some birthday cake as you (see). 5. This watch generally (keep) perfect time, but these days it (not work) properly. 6. — Could you speak louder, please? I can't hear anything you (say). - I (speak) loudly enough and (not understand) why you (not follow). 7. - You (get) on all right? - Oh, yes. I (get) on fine. 8. At present we (live) in a very small apartment. My mother has sold our old flat. 9. - When you (meet) Bob? - I (meet) him at 12 o'clock tomorrow. 10. She (think) we are wrong. 11. Be quiet. I (think). 12. — Hello. We are at Andrew's. He (have) a party. - Oh, really? I hope you (have) a good time. 13. - What your son usually (have) for breakfast? - Occasionally he (have) bacon and eggs, a sandwich or a carton of yogurt. He (not have) any porridge as a rule. 14. It's a national holiday today. The shops (work)?

Sure! Here are the sentences completed with the correct form of the verbs in either the present simple or present progressive tense:

1. • Where does Mr. Ross live? - I do not know. I think he lives in the next street.
2. • Does John smoke? - He used to. But now he never touches a cigarette. He gradually is becoming quite fit.
3. Ice melts in a warm climate.
4. I usually do not eat sweet things. But today it's Tom's birthday, so I am eating some birthday cake as you can see.
5. This watch generally keeps perfect time, but these days it is not working properly.
6. — Could you speak louder, please? I can't hear anything you are saying. - I am speaking loudly enough and do not understand why you are not following.
7. • Are you getting on all right? - Oh, yes. I am getting on fine.
8. At present we are living in a very small apartment. My mother has sold our old flat.
9. • When are you meeting Bob? - I am meeting him at 12 o'clock tomorrow.
10. She thinks we are wrong.
11. Be quiet. I am thinking.
12. — Hello. We are at Andrew's. He is having a party. - Oh, really? I hope you are having a good time.
13. • What does your son usually have for breakfast? - Occasionally he has bacon and eggs, a sandwich, or a carton of yogurt. He does not have any porridge as a rule.
14. It's a national holiday today. Do the shops work?

If you have more questions or need further explanations, feel free to ask!